1. Field
Embodiments of the present invention relate to a cooling apparatus using a magnetocaloric effect, and method.
2. Description of the Related Art
Cooling apparatuses having a cooling effect by compressing and expanding a gaseous refrigerant, such as chloro fluoro carbon (CFC), are widely used domestically and in industry. However, CFC that may be used as the gaseous refrigerant destroys the ozone layer and causes global warming and is recognized as a major contributor to environmental destruction, and thus new cooling apparatuses to replace these cooling apparatuses using CFCs are desired.
A magnetic cooling apparatus is a cooling apparatus using a magnetocaloric effect. The magnetocaloric effect may be defined as a phenomenon in which the temperature of a magnetic material is raised when a magnetic field is applied to the magnetic material, and is lowered when the magnetic field is removed from the magnetic material. Such a magnetocaloric effect is based on the law of entropy that when the magnetic field is applied to the magnetic material, particles of the magnetic material are arranged. Thus, the temperature of the magnetic material may be raised. When the magnetic field is removed from the magnetic material, arrangement of the particles of the magnetic material may become non-uniform. Thus, the temperature of the magnetic material may be lowered. The magnetic cooling apparatus exhibits a cooling effect using such a temperature difference.
Magnetic cooling apparatuses include a reciprocation type magnetic cooling apparatus in which a magnetic regeneration unit including a magnetic material reciprocates at the inside and the outside of a magnetic field formed by magnets to induce temperature change of a magnetocaloric material, and a rotation type magnetic cooling apparatus in which magnets are rotated, for example, around an annular container provided with a magnetic regeneration unit including a magnetic material installed therein, and thus a change of a magnetic field to the magnetic regeneration unit may be formed to induce a temperature change of a magnetocaloric material in the magnetic regeneration unit.
Magnetic cooling apparatuses may use a motor as a power source to achieve reciprocating motion or rotating motion of the magnetic regeneration unit, and require a power transmission system to convert driving force of the motor into the reciprocating motion or the rotating motion of the magnetic regeneration unit. Therefore, miniaturization of the magnetic cooling apparatuses may be difficult and energy efficiency in driving the magnetic cooling apparatuses may be low.